Biotechnology Lecture Notes

Solid State Fermentation Technology: Examples, Advantages and Disadvantages


Solid State Fermentation (SSF)
(Solid State Fermentation: Technology, Advantages and Disadvantages)

What is Solid State Fermentation (SSF)?

In Solid State Fermentation, also called Solid Substrate Fermentation or SSF, the fermentation substrate or media will be in the solid state. Here the microorganisms are grown on a solid substratum in the absence or near absence of free water. The moisture content of the substratum in SSF is usually maintained below 15%. The solid state fermentation is most commonly carried out for the production of fermented food products such as bread, fermented fish, meat, yogurt, cheese and pickles. The microbial fermentation increases the nutrient content and flavor of food products. It also increases the digestibility of foods. The cultivation of edible mushrooms on a suitable substratum is also a solid state fermentation process.

Pleurotus djamor

Mushroom Cultivation (wikipedia)

Substrates / Media in Solid State Fermentation


The substrates commonly used in SSF are usually very complex, heterogeneous and are insoluble in water. These substrates include cereals grains, wheat bran, lingo-cellulosic materials such as wood shavings, sawdust, molasses etc. In most of the cases, the substrate or the raw materials were undergone through a pre-treatment such as soaking, boiling in water, mechanical pre-treatment or chemical treatment. These pre-treatments increase the bioavailability of nutrients for the microbes to act on them.

Instrumentation and Growth Kinetics in Solid State Fermentation

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Biotechnology Lecture Notes

Advantages and Disadvantages of Animal Cell Culture (Short Lecture Notes)

animal cell culture advantages and limitations

Advantages and Disadvantages of Cell / Tissue Culture

Tissue culture is an aseptic in vitro culture of animal or plant cells in a precisely controlled environmental condition. The term “Tissue Culture” was for the first time coined by Thomas Burrows. Even though the in vitro culture of prokaryotes and both plant and animal cells are possible now, the term ‘Tissue Culture’ generally denotes to Animal Cell / Tissue culture. The term ‘Plant Tissue Culture’ symbolizes the in vitro culture of plant cells.

In cell culture the cells are maintained in an artificial environment consists of a suitable culture vessel containing a culture medium. The medium supplies all the nutrients, growth factors, and required gases for the growth of the cells. Moreover, the physiochemical environment of the culture system is strictly monitored most probably through automated systems. The control of the physiochemical environment in the culture system is one of the most important advantages of cell culture system. However, the tissue culture process is not always profitable and there are a plenty of difficulties in maintaining the cells in in vitro conditions. The present post describes the Advantages and Disadvantages of animal cell or tissue culture techniques.

Advantages of Animal Cell Culture:

Ø  Physio-chemical environment in the culture such as pH, temperature, osmolarity and level of dissolved gases can be precisely controlled in the in vitro system.

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Biotechnology Lecture Notes

Applications of Restriction Endonuclease Enzymes in Biotechnology (Short Notes)

Restriction enzymes in Genetic Engineering

Applications of Restriction Enzymes
(The Significance / Importance and Uses of Restriction Endonucleases in Biotechnology)

Restriction endonucleases (also called as molecular scissors) are a class of nuclease enzymes which cut the DNA strand at precise locations. They are specific endonuclease enzymes in the cells which first recognize the specific sequence (called restriction sites) within the DNA strand and cleave the phosphodiester backbone of the DNA at specific sites. The Nobel Prize in 1978 (in Physiology and Medicine) was shared by Werner Arbor, Daniel Nathans and Hamilton Smith for the discovery of restriction enzymes and their applications in molecular genetics. Restriction enzymes are now an inevitable tool for the manipulation of DNA in various recombination studies both in vitro and in vivo. The main applications of restriction enzymes are:

(1). Construction of Restriction Maps

(2). Construction of DNA Fingerprints

(3). Recombinant DNA Technology (rDNA Technology)

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Biotechnology Lecture Notes

Batch Fermentation vs Continuous Fermentation Process: Similarities and Differences – A Comparison Table

Difference continuous and batch fermentation

Batch Fermentation vs Continuous Fermentation Process
(Similarities and difference between Batch Fermentation and Continuous Fermentation Process)

Batch Fermentation and Continuous Fermentation are the two commonly adopted Industrial Fermentation methods for the scale production of microbial biomass or metabolites.

Batch Fermentation: Here the fermenter is first filled with the raw material (carbon source). Then the microbes are added and allowed to ferment the raw material under optimum pH and aeration. The products remain in the fermenter until the completion of fermentation. After fermentation, the products are extracted and the fermenter is cleaned and sterilized before next round. Thus here the fermentation is done as separate batches.

Continuous Fermentation: Here the exponential growth rate of the microbes is maintained in the fermenter for prolonged periods of time in by the addition of fresh media are regular intervals. The metabolite or the product of fermentation is extracted for the overflow from the fermenter. Thus unlike batch fermentation, in continuous fermentation, the fermentation process never stops in between and it continues to run for a long period of time with the addition of nutrients and harvesting the metabolites at regular intervals.

The present post describes the Similarities and Differences between Batch Fermentation and Continuous Fermentation Process as a Comparison Table.

Similarities between Batch Culture and Continuous Culture Fermentation Methods

Ø  Both are industrial fermentation methods for the large scale production.

Ø  Both methods can be used for the production of microbial biomass or products.

Ø  Both run under controlled environmental conditions

Ø  The mechanical components of fermenter is almost similar in both types

Difference between Batch Fermentation and Continuous Fermentation Process

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Biotechnology Lecture Notes

Industrial Fermentation Process (Batch, Fed-batch and Continuous Fermentation)

types of fermentation process

Fermentation Technology
(Types of Industrial Fermentation Processes)

Fermentation: An art from the past, a skill for the future…
Brain McNeil

What is fermentation?

Ø  Fermentation is a metabolic process which converts carbohydrates to alcohols, organic acids or gases by the activity of enzymes of microbial origin.

Ø   Microbes involved in fermentation process: Bacteria and Fungi.

Ø  The process of anaerobic respiration in the muscle cells of animals during exercise which produce lactic acid is also a type of fermentation.

Ø  The technique of fermentation was very ancient in origin.

Ø  Egyptians and Sumerians had the knowledge of the technique of converting starchy grains to alcoholics.

Ø  For a microbiologist, the word ‘fermentation’ means many processes such as:

$   A method of mass cultivation of microbes under aerobic or anaerobic conditions.

$   Any biological process occurs in the absence of oxygen.

$   Spoilage of food by microbial activity.

$   Production of alcoholic beverages, organic acids, antibiotics or biopolymers

$   Partial oxidation of carbohydrates

What is industrial fermentation?

Ø  The intentional use of fermentation technology for the large scale production of microbial biomass or metabolites is called industrial fermentation.

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